Expansion joint



Patented Apr. 26, 1938 EXPANSION JOINT Eugen Hutaenlaub, Stuttgart,Germany, assignor to the firm Paul Lechler, Stuttgart, Germany NoDrawing. Application February 11, 1934, Serial No. 711,826. In GermanyMarch 4, 1933 3 Claims. (01. 94-418) .The present invention relates to acomposition of matter useful in filling cracks, expansion joints, seams,crevices and grooves in concrete highways, stone, brick, cemented orconcrete 5 walls. chimney stacks, supporting columns or indeed anystructure or structural element exposed to the weather. Thefillingmaterial may also be used in patching and filling up the cracks,fissures, grooves, crevices and the like which may oexist in wood,granite, sandstone and the-like.

It is generally known that in localities in which the temperaturevariation from the beginning to the end of the year is great, thatmasonry, for example, may develop serious and deep-seated cracks orfissures'permitting the ingress of moisture with its destructiveeffects, and 'of course the appearance of the masonry also will be veryunsightly. This proposition may be illustrated with reference toconcrete highways in the northeast section of the United States, wherefrom January to the following December, the range of atmospherictemperature may be from 105 F., to 14 F., below zero. Under theseextreme variations of temperature, a concrete highway is apt to developserious cracks, crevices and fissures.

- The internal stress caused by such extreme temperature variation mayso disrupt the road sur-- face as to require extensive repairs in theform of filling and patching of large .areas.

an Prior to the present invention it has been the practice to patch orfill in crevices, expansion joints, pits, grooves and the like, producedin concrete and other material with asphalt. The patching of concrete orother light colored building material with asphalt presents of course anunsightlyappearance, due to. the black colorot asphalt; For example, aconcrete highway which has suffered deterioration due to the formationof cleepseated cracks and fissures, when patched with asphalt presentsan unsightly appearance due to the contrast between the black asphaltand the light colored concrete road. This defect has been the subject ofexperimentation and it has been proposed to lighten asphalts by theremoval of the so-called asphaltenes. The asphaltenes are substances'ofobscure chemical composition present in asphalts, and their removalresults in a lightening of the color of the remaining asphalt. Howeverthe removalof the asphaltenes causes a decrease in the plasticity of theasphalt. pearance of asphalt; it is also pointed out that duringextremely hot summer weather the asphalt used in-patching masonry orconcrete becomes soft, and if it is used to patch the walls of admixedwith fillers.

a building it often happens that the asphaltsof- ,tens to the extentthat it becomes somewhat fluid,

and therefore it is apt to flow out of the crevices. or fissures ofvertical walls in which it has been placed. Furthermore, while asphaltis a heat 5 plastic substance, it is a substance which possessesvirtually no elasticity, and as a result sudden shocks are apt todisrupt and disintegrate the solid asphalt.

The present applicant overcomes the diflicul- 1o ties and deficienciesencountered in the use of asphalt, by employing a rubber latexcom-position Rubber latex asis well known is a light colored substance,and because of this fact it may be colored with any pigment, 15

lake or dyestutf to produce a color which may be 1 made to matclr thestructural elements which it may be used to patch. The applicant hasfound that the addition of flne fibres of asbestos to latex gives amixture oi. light color, and there- 20 fore when latex is mixed withfine asbestos fibres, the mass has about the color and appearance ofconcrete or cement. The use of pigments such as iron-oxide, chromegreen, ochre, carbon black and the like gives a color which may be usedto 25 match a colored building or other structure.

Fillers such as zinc oxidemay also be used and a rubber vulcanizer suchas sulphur or sulphur chloride maybe added. 7

The kind'and the amount of mineral organic 30 substance that should bemixed with thelatex depends entirely upon the physical and chemicalpropertiesthat are desired, and these can be varied within wide limitsto suit the purpose for which .it is to be employed. .It should bepointed 5 out thatcaeutchouc is a substance which is resistant to bothacid and alkali.

The asbestos/fibres impart to the mass an extraordinary toughness andresistance to extreme weather conditions. The mass also possesses 40elasticity after the breakage of the latex dispersion. The breaking ofthe dispersion caused by the removal of water eiiects a cementing of theparticles of caoutchouc with each other and with the filler material, sothat the mass becomes quite dense.

I "treated with ammonia or simflar alkali is not 50 In addition to theunsightly aplike. I v 55 Without limiting the invention to the precisedetails therein specified, the following specific examples illustratethe present invention and no doubt, numerous modifications, within thespirit of the present invention other than those disclosed in the saidexamples, will be suggested to those skilled in the present art.

Example I 40 parts by weight of an aqueous dispersion of rubber latex ofthe usual technical grade, and which has been preserved with ammonia orsimilar alkali is mixed with 2 parts by weight of Turkey red oil andthen 30 parts by weight of asbestos fibres consisting of a mixture ofasbestos in powdered form and fibres not greater than 1 mm. in length,are added. 5 parts by weight of zinc oxide, 22 parts by weight ofasbestos fibres varying in length irom 1 to 5 mm. and finally 1 part byweight of flowers of sulphur are added to the above mixture. Theingredients are thoroughly mixed. The resulting mixture is a lightcolored, pasty mass, which when used to fill in or patch cracks,fissures, grooves and the like, aiiords a strong and elastic sealagainst the ingross of frost and moisture. The material itself possesseshigh strength and coherency. The mass may be given the appearance andcolor of sandstone by adding ochre.

Example I I The following ingredients are thoroughly mixed together:

Parts by weight Rubber latex 50 Ammonium oleate 3 Asbestos fibres ofvarying length but not greater than 1 mm 47 In this modification theasbestos fibres are so intermixed with the rubber particles as to give afirmbond and the mass possesses good mechanical strength and elasticityand does not require the addition of fillers to produce this effect.

Example III The following ingredients are thoroughly mixed together:

Parts by weight 8 The above mixture is stirred until a homogeneousmixture results.

The above mentioned emulsion is compounded by thoroughly mixing Parts byweight Solvent nap Ammonium oleate 3 Water- 47 The rubber latex used inthe present process may be any good commercial grade containing at least12% and not more than 60% rubber solids. The solvent naphtha used inpreparing the emulsion described in Example III is. that fraction ofcoal tar oil distilling between 155 C. and 180 C.

The vulcanizing agent such as sulphur or sulphur chloride describedabove, may be substituted by any known cold vulcanizing agent, andfurthermore rubber accelerators such as the aryl substituted guanidines,mercapto benzothiazoles or the like may be used.

The filling and patching material described by the present invention maybe carefully worked into the cracks and crevices intended to be filled.It is sometimes advisable, however, to apply a priming coat of ordinaryrubber latex or a ground paint.

The above mentioned solvent naphtha may be substituted by any knownsolvent for rubber such as benzol, xylol, toluol, carbontetrachloride.

The term voids" includes the space between concrete slabs in a pavementor architectural structure such as the restraining wall of a dam, andalso includes cracks, crevices, seams and the like in the body of saidslabs.

I claim:

1. In combination, pavement or structural slabs in spaced relationshipto each other and in the spaces thus formed a material forming anexpansion joint comprising asbestos admixed with natural rubber latexand also containing an organic solvent, said material being adapted toexpand and contract responsive to changes in the size of the said spacescaused by thermal expansion and contraction of the said slabs, to filland seal the said spaces and which seal is durable and highly resistantto outdoor exposure.

2. In combination, pavement or structural slabs in spaced relationshipto each other and. in the spaces thus formed a material forming anexpansion joint comprising asbestos admixed with natural rubber latex,an organic solvent, a stabilizing agent and a rubber vulcanizing agent,said material being adapted to expand and contract responsive to changesin the size of the said spaces caused by thermal expansion andcontraction, to fill and seal the said spaces and which seal is durableand highly resistant to outdoor exposure.

3. In combination, pavement or structural slabs in spaced relationshipto each other and in the spaces thus formed a material forming anexpansion joint comprising 28 to 50 parts by weight of rubber latex and47 to 52 parts by weight of asbestos and an organic solvent, saidmaterial being adapted to expand and contract responsive to changes inthe size of the spaces caused by thermal expansion and contraction ofthe said spaces, and which seal is durable and highly resistant tooutdoor exposure.

EUGEN HUTZENLAUB.

